1.4 GHz Source Counts Melanie Gendre Walter Max-Moerbeck Mitch Mickaliger Katie Rabidoux Under the supervision of Brian Mason and Jim Condon

Overview Used GBT to measure continuum emission in a random patch of sky Calculated source counts Distribution of sources as function of flux density Large GBT beam size (9') can cause confusion Detection of a group of sources as one source

Observations Used GBT (L-Band)‏ 1410 MHz Continuum Mapped 10º x 1º area 9' beam, Nyquist sampled Bonn 1420 MHz Survey Reich, 1982, A&AS48, 219. Reich and Reich, 1986, A&AS63, 205.

Parameters Calibration source 3C286 G = 1.69 K/Jy FWHM = 9 arcmin Effective Area = 4664 m^2 Aperture efficiency = 0.59 antenna solid angle = 9.84 10^-6 srad mean beam solid angle = 5.46 10^-6 srad mean beam efficiency = 0.55 Tsys = 14.5 K With an integration time of 0.2 s, and bandwidth of 50 MHz we get Tnoise = 4.6 mK Snoise = 2.71 mJy

Reduction

Results For a distribution of sources at a given flux density, the number of sources can be described by the power law n(S) = k * S-γ where k is a normalization constant and γ is the power law coefficient

Results: Source Count {gamma, k} {{1.7, 1895.64}, {1.9, 1002.79}, {2.1, 449.769}, {2.3, 174.458}} {S^2.5 n(s)} {2.23693, 2.22059, 2.13258, 1.98149}